Adjustable firearm stock

ABSTRACT

An adjustable stock comprises a frame and a housing that slides telescopingly with respect to the frame between at least two configurations: a shortened configuration and a lengthened configuration. Preferably there is at least one configuration of intermediate length. To permit the adjustment of the stock, a lever arm, biased in a locking position, is pressed, whereupon it unlocks the housing from the frame and allows the user to slide the housing with respect to the frame from one configuration to another. The lever arm has a projection on the end that is either seated in one of several recesses in the housing, thereby locking the frame to the housing, or slidable within a channel formed in the housing and running from one recess to another.

CROSS REFERENCE TO RELATED PATENTS

None.

BACKGROUND OF THE INVENTION

The present invention relates to firearm stocks and adjustable firearmstocks in particular.

A typical rifle or machine gun will include a stock that enables theuser to brace the firearm against his shoulder. The stock is fastened toa receiver and a barrel. Most stocks are sized for a typical adult andare not adjustable. Adjustable stocks are most often found in highperformance, competition rifles, that allow the user to adjust the stockto the particular dimensions of the user. These adjustable stocks can bemoved between a shorter configuration and a longer configuration bytelescopingly sliding one part of the stock with respect to another andthen securing the stock to the frame at the preferred configuration.Once fixed to the dimensions of the user, they are locked in place andonly rarely adjusted a second time.

Military firearm stocks, on the other hand, may need to be configuredfor a particular mission, and possibly reconfigured during the missionfor a change in use rather than for the body dimensions of the user. Forexample, a shorter stock may be preferred for its easier maneuverabilityin close quarters in urban fighting; a longer stock may be preferred forshooting at a distance. In either case, the adjustable stock willrequire some way to lock the stock in its preferred configuration. Inmilitary applications, the adjustability must be quicker and easier,driven by mission rather than the personal body dimensions of a user.

Thus there remains a need for a better way to adjust the length of astock for military applications.

SUMMARY OF THE INVENTION

According to its major aspects and briefly recited, the presentinvention is an adjustable stock. The present stock comprises a frameand a housing that slides telescopingly with respect to the framebetween at least two configurations: a shortened configuration and alengthened configuration. Preferably there is at least one intermediateconfiguration. To permit the adjustment of the stock, a lever arm,biased in a locking position, is pressed, whereupon it unlocks thehousing from the frame and allows the user to slide the housing withrespect to the frame from one configuration to another. The lever armhas a projection on the end that is either seated in one of severalrecesses in the housing or slidable within a channel formed in thehousing and running from one recess to another.

An important feature of the present invention is the locking lever,which allows the user to quickly, reliably and easily change theconfiguration of the stock. Merely by squeezing the locking lever, theuser is able to unlock the housing with respect to the frame. Releasingthe locking lever assures that the housing and frame will lock when theyin one of the configurations.

Another important feature of the present invention is the combination ofa pin positioned in the stock that prevents excessive rearward movementof the locking lever, the projection on the end of the lever, and thechannel the projection slides in when the housing is moved relative tothe frame. Only a small amount of travel of the locking lever isrequired to move the projection out of its recess and thereby unlock thehousing from the frame; excessive movement of the locking lever, ifpermitted, would cause the projection on the lever to become misalignedwith respect to the channel. The pin in the stock prevents excessivemovement of the locking lever, and, accordingly, misalignment.Additionally, the channel assures controlled movement of the projectionfrom one locking position to the next.

These and other features and their advantages will be apparent to thoseskilled in the art of firearm design from a careful reading of theDetailed Description of Preferred Embodiments accompanied by thefollowing drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings,

FIG. 1A is a perspective view of a firearm with a stock according to apreferred embodiment of the present invention, the stock in theshortened configuration;

FIG. 1B is a detail of the firearm of FIG. 1A showing the stock in alengthened configuration;

FIG. 2 is a side exterior view of the stock in the shortenedconfiguration with its locking lever pulled, according to a preferredembodiment of the present invention

FIG. 3 is a side exterior view of the stock of FIG. 2 in the extendedconfiguration and with its locking lever released;

FIG. 4 is a side cross sectional view of the shortened stock of FIG. 2;and

FIG. 5 is a side cross sectional view of the lengthened stock of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a new, replacement stock for an existingfirearm and a new firearm equipped with the present stock. The stock ischaracterized by the fact that the user can quickly and easily lengthenand shorten the stock without tools.

Referring now to the figures, FIG. 1A illustrates a light-weight machinegun 10 having a barrel 12, a receiver 14, and a stock 16. Barrel 12 hasa receiver end 22 connected to a first end 24 of receiver 14. Anopposing, second end 26 of receiver 14 is attached to a first end 28 ofstock 16. Ammunition (not shown) is inserted into a breech 30 ofreceiver 14 and fired through barrel 16 in the usual manner using a firecontrol system. Except for a portion of trigger 18, the fire controlsystem is housed in receiver 14.

Although FIG. 1A shows light-weight machine gun 10, any firearm capableof having a stock attached to it may be improved with the present stock16. Furthermore, the operation and construction of firearms,particularly standard military rifles and machine guns, are well known.

FIG. 1B illustrates a detailed view of a firearm focused on stock 16 anda portion of receiver 14. It will be clear from a comparison of stock 16in FIGS. 1A and 1B that stock 16 in FIG. 1A is shorter and stock 16 inFIG. 1B is longer. In particular, stock 16 has a frame 32 and a housing34 slidably carried by frame 32. Housing 34 slides over frame 32 in atelescoping fashion between a shortened configuration, as illustrated inFIG. 1A, and a lengthened configuration, as illustrated in FIG. 1B. Aswill be described, stock 16 may have at least one intermediateconfiguration.

Stock has a cheek piece 36 and butt plate 38, a rear sling attachment 40and a front sling attachment 42. When first end 28 of stock 16 isdisconnected from second end 26 of receiver 14, a receiver coupler 44can be seen with an upper pin connection 46 and a lower pin connection48. A portion of a locking lever 56 is visible along the bottom of frame32. Acting somewhat like a trigger that can be pulled or squeezed torelease the internal locking mechanism and thereby allow thereconfiguration of stock 16 between the shortened configuration, asshown in FIG. 1A as well as FIG. 2 and FIG. 4, and the lengthenedconfiguration, as shown in FIG. 1B, FIG. 3 and FIG. 5.

The cross sectional views of FIGS. 4 and 5 illustrate the operation ofthe locking mechanism. As the user squeezes exterior portion 60 oflocking lever 56, locking lever 56 pivots about a pivot pin 62. Itsdistal end 64 rotates counter-clockwise when stock 16 is viewed from theleft and pulls a projection 66 carried on its distal end downward andout of a recess 68 formed in a channel 70 in frame 32. Once projection66 is clear of recess 68, housing 34 is free to slide with respect toframe 32. When housing 34 is sliding, projection 66 remains withinchannel 70, and thus channel 70 acts as a guide or cam race forprojection 66, keeping it confined to a narrow track. Projection 66 thusserves two functions. First, when in recess 68, it holds frame 32 lockedto housing 34. Second, when out of recess 68 but still in channel 70, itserves as a cam, an alignment device, to keep housing 34 aligned withframe 32 when the two are moving relative to each other.

It is important for alignment and repeatable operation of frame 32 andhousing 34 of stock 16 to limit the travel of exterior portion 60 oflocking pin 56 so that projection 66 does not pivot clear of channel 70.It is also important to urge projection 66 into recess 68. Therefore, aretaining pin 76 biased by a spring 78 is positioned behind exteriorportion 60 to limit its rearward travel and urge it forward. Whenlocking lever 56 is pressed against a first end retaining pin 76, pin 76moves rearward against the urging of spring 78 until pin meets buttplate 38, whereupon it and locking lever 56 can move no further.

It is intended that the scope of the present invention include allmodifications that incorporate its principal design features, and thatthe scope and limitations of the present invention are to be determinedby the scope of the appended claims and their equivalents. It alsoshould be understood, therefore, that the inventive concepts hereindescribed are interchangeable and/or they can be used together in stillother permutations of the present invention, and that othermodifications and substitutions will be apparent to those skilled in theart from the foregoing description of the preferred embodiments withoutdeparting from the spirit or scope of the present invention.

1. A stock for a firearm, said stock comprising: a frame; a housingslidably carried by said frame between a shortened configuration and alengthened configuration; a locking lever pivotally carried by saidhousing and pivotable between at least one locking position and anunlocking position, said locking lever locking said frame to saidhousing when said locking lever is in said at least one lockingposition; and means for urging said locking lever into said at least onelocking position, said urging means limiting movement of said lockinglever from said at least one locking position to said unlockingposition.
 2. The stock as recited in claim 1, wherein said locking leveris adapted to lock said frame to said housing in said shortenedconfiguration and in said lengthened configuration.
 3. The stock asrecited in claim 1, wherein said frame has two recesses formed thereinand said locking lever carries a projection, each recess of said tworecesses dimensioned for receiving said projection, said locking leverlocking said frame to said housing when said projection is receivedwithin said each recess.
 4. The stock as recited in claim 1, whereinsaid urging means further comprises: a pin; a spring; and a butt plate,said spring urging said locking lever into said locking position andsaid pin limiting movement of said locking lever when said pin meetssaid butt plate.
 5. The stock as recited in claim 1, wherein saidlocking lever has a first end and an opposing second end, said first endextending outside of said housing, said second end being inside saidhousing.
 6. The stock as recited in claim 5, wherein said second endcarries a projection and said frame has at least two recesses, saidprojection of said locking lever being received by either recess of saidat least two recesses when said frame is locked to said housing.
 7. Thestock as recited in claim 6, wherein said frame has a channel formedtherein and running between said at least two recesses, and wherein saidprojection moves within said channel when said frame is moving withrespect to said housing.